Many people asked me of what they need to make a media player in delphi.
So i write these tutorial that anybody can create it’s own media player.
What you’ll need:
1) Delphi
2) BASS.DLL(http://un4seen.com)

What is BASS?
BASS is an audio library for use in Windows and Mac OSX software. Its purpose is to provide developers with powerful and efficient sample, stream (MP3, MP2, MP1, OGG, WAV, AIFF, custom generated, and more via add-ons), MOD music (XM, IT, S3M, MOD, MTM, UMX), MO3 music (MP3/OGG compressed MODs), and recording functions. All in a tiny DLL, under 100KB* in size.

Now lets get started

1) Create a new project
2)In the form create function we must initialize BASS.DLL

procedure TForm2.FormCreate(Sender: TObject);
begin
BASS_Init(-1,44100,0,handle,0); //initialize bass
end;

Now let’s go to play section.
Put a open dialog, a scrollbar and a button to the form.
On the button on click function do something like this:

var
channel: HSTREAM;
begin
  OpenDialog.Title  := 'Open Files';
  OpenDialog.Filter := 'All files|*.*';
  if channel0 then
  begin
  BASS_StreamFree(channel);  //destroy any previous channel if exists
  channel:=0;
  end;
  if not OpenDialog.Execute then exit;
  Channel := BASS_StreamCreateFile(FALSE, PChar(OpenDialog.FileName), 0, 0,BASS_UNICODE); //create the stream
  scrollbar1.Max:=round(BASS_ChannelBytes2Seconds(channel, BASS_ChannelGetLength(channel, BASS_POS_BYTE))); //retrieve media length in seconds
 BASS_ChannelPlay(channel,0); // play the stream
end;

Now if you Pause,Stop functions:

For pause you’ll need to call this function:

 BASS_ChannelPlay(Channel, False);

To stop you’ll need to call this function:

 BASS_ChannelStop(Channel);

Of course you’ll need to set position to the song. This is a very simple task:

BASS_ChannelSetPosition(Channel, BASS_ChannelSeconds2Bytes(Channel,  scrollbar.Position), BASS_POS_BYTE);//set the channel position

Now let’s say you want to display a waveform like winamp does. No problem, this can be done like this:
1) create a new unit and put this code in it.

unit osc_vis;
{ Oscilloscope Visualyzation by Alessandro Cappellozza
  version 0.8 05/2002
  http://digilander.iol.it/Kappe/audioobject
}

interface
  uses Windows, Dialogs, Graphics, SysUtils, CommonTypes, Classes;

 type TOcilloScope = Class(TObject)
    private
      VisBuff : TBitmap;
      BackBmp : TBitmap;

      BkgColor : TColor;
      ScopeOff : Integer;
      PenColor : TColor;
      DrawType : Integer;
      DrawRes  : Integer;
      FrmClear : Boolean;
      UseBkg   : Boolean;

    public
     Constructor Create (Width, Height : Integer);
     procedure Draw(HWND : THandle; WaveData : TWaveData; X, Y : Integer);
     procedure SetBackGround (Active : Boolean; BkgCanvas : TGraphic);

     property BackColor : TColor read BkgColor write BkgColor;
     property Offset : Integer read ScopeOff write ScopeOff;
     property Pen  : TColor read PenColor write PenColor;
     property Mode : Integer read DrawType write DrawType;
     property Res  : Integer read DrawRes write DrawRes;
     property FrameClear : Boolean read FrmClear write FrmClear;
  end;

 var OcilloScope : TOcilloScope;

implementation

     Constructor TOcilloScope.Create(Width, Height : Integer);
      begin
        VisBuff := TBitmap.Create;
        BackBmp := TBitmap.Create;

          VisBuff.Width := Width;
          VisBuff.Height := Height;
          BackBmp.Width := Width;
          BackBmp.Height := Height;

          BkgColor := clBlack;
          ScopeOff := 50;
          PenColor := clWhite;
          DrawType := 0;
          DrawRes  := 1;
          FrmClear := True;
          UseBkg := False;
      end;

     procedure TOcilloScope.SetBackGround (Active : Boolean; BkgCanvas : TGraphic);
      begin
        UseBkg := Active;
        BackBmp.Canvas.Draw(0, 0, BkgCanvas);
      end;

     procedure TOcilloScope.Draw(HWND : THandle; WaveData : TWaveData; X, Y : Integer);
        var i, YPos : LongInt; R, L : SmallInt;
       begin
       if FrmClear then begin
         VisBuff.Canvas.Pen.Color := BkgColor;
         VisBuff.Canvas.Brush.Color := BkgColor;
         if UseBkg then
           BitBlt(VisBuff.Canvas.Handle,         // Destination
                  0, 0,                          // X, Y (target pos)
                  VisBuff.Width, VisBuff.Height, // Size to copy
                  BackBmp.Canvas.handle,         // Source
                  0, 0,                          // X, Y (source pos)
                  SrcCopy)                       // plain copy
         else
           VisBuff.Canvas.Rectangle(0, 0, VisBuff.Width, VisBuff.Height) // only if no background
       end;

        VisBuff.Canvas.Pen.Color := PenColor;
            R :=  SmallInt(LOWORD(WaveData[0]));
            L := SmallInt(HIWORD(WaveData[0]));
            YPos := Trunc(((R + L) / (2 * 65535)) * ScopeOff) ;
            VisBuff.Canvas.MoveTo(X , Y + YPos);

         for i := 1 to 256 do begin
            R := SmallInt(Loword(WaveData[i * DrawRes]));
            L := SmallInt(HIword(WaveData[i * DrawRes]));
            YPos := Trunc(((R + L) / (2 * 65535)) * ScopeOff) ;

              case DrawType of
                0 : VisBuff.Canvas.lineto(X + i, Y + YPos);

                1 : begin
                      VisBuff.Canvas.MoveTo(X + i, Y);
                      VisBuff.Canvas.lineto(X + i, Y + YPos);
                    end;

                2 : VisBuff.Canvas.Pixels[X + i,  Y + YPos] := PenColor;
              end;
         end;

          BitBlt(HWND, 0, 0, VisBuff.Width, VisBuff.Height, VisBuff.Canvas.Handle, 0, 0, srccopy)
       end;
end.

2) Put a tpaintbox and a ttimer on the form and put this code to the timer. Also you’ll have to set timer interval to at least 30ms.

var  WaveData  : TWaveData;
begin
 if BASS_ChannelIsActive(Channel)  BASS_ACTIVE_PLAYING then Exit;
 BASS_ChannelGetData(Channel, @WaveData, 2048);
 OcilloScope.Draw (PaintFrame.Canvas.Handle, WaveData,0,50);

This will display a nice waveform of the media that you are playing.

So…i end for now this tutorial, in the hope that you’ll apreciate it.